Update the time zone picker to work with location containing diacritics

Currently, looking for a location containing diacritics (e.g. accents) requires the user to type in exactly those characters. With this change, diacritics are ignored and the strings are returned if they match (using startsWith).
For example, looking for "reun" will show you "Réunion".

Bug: b/364245352
Test: atest tests/robotests/src/com/android/settings/datetime/timezone/BaseTimeZoneAdapterTest.java
Change-Id: I507a9ebc1c830ad3162fb2382814935fc337328d
Flag: EXEMPT bugfix